This invention relates to an image forming apparatus having a function for checking copying of a secret document and suitably adapted as an electronic copying machine.
Conventional copying machines have functions for copying original images in equal, enlarged and reduced sizes.
Since conventional copying machines can copy a secret document as well as a normal document, it is difficult to completely protect a secret even if the secret document is not brought out. It is preferable if copying of a secret document can be detected.
In addition, original images often contain unnecessary portions. However, many conventional copying machines cannot selectively copy only a desired region of the original image.
Therefore, if a copying machine is multifunctioned so that secret documents are protected from being copied, and a copying region can be selected, this will result in convenience. However, a conventional multifunctional copying machine often has a complicated arrangement.